Method and apparatus for pumping liquid from a well using wellbore pressurized gas

Abstract

There is provided a method and apparatus for removing liquid from a well using well bore pressurized gas. A U-shaped tube having a small orifice near the bottom thereof is received in the well. The upper portions of both legs of the tube are connected to well bore pressurized gas. A liquid sensor is received in one leg of the tube. When liquid flowing into the tube through the orifice rises to the level of the sensor, a valve, which is connected to one leg of the tube, is opened and the well head pressurized gas forces the liquid out of the tube and then out of the well.

We claim: 
     
       1. A method for removing liquid from a well bore and utilizing a tubing means having a gas inlet portion and a liquid discharge portion and a first valve connected to the liquid discharge portion, the tubing means having an opening therein comprising the steps of: flowing liquid from said well bore into said tubing means through said opening;   flowing pressurized gas from the well bore into the gas inlet portion;   opening said first valve;   moving the liquid from said tubing means through the liquid discharge portion and out of the well.   
     
     
       2. A method as set forth in claim, 1 further including the step of: sensing the amount of liquid in said tubing means prior to opening said first valve.   
     
     
       3. A method as set forth in claim 2 wherein a second valve is connected to the liquid discharge portion and to the well and further including the steps of: opening said second valve and receiving pressurized gas in said liquid discharge portion;   closing said second valve when said first valve is opened.   
     
     
       4. A method as set forth in claim 1 further including the steps of: sensing the passage of liquid through said liquid discharge portion;   closing said first valve and opening said valve in response to said sensing of the passage of liquid.   
     
     
       5. A method as set forth in claim 1 further including the step of filtering the liquid prior to its entering the tubing means through said opening. 
     
     
       6. A method as set forth in claim 4 further including a second valve connected to said liquid discharge line and to the bore hole and further including the steps of: closing said second valve while said first valve is open and opening said second valve upon the closing of said first valve. 
     
     
       7. A method as set forth in claim 1 further including the step of sensing well bore gas pressure and measuring the time interval from the initiation of the pumping cycle to the time for the liquid slug to reach the top of the well bore and in turn determining the quantity of liquid passing through the liquid discharge portion since the time interval will be proportional to the length of the liquid slug. 
     
     
       8. An apparatus for removing liquid from a well using well bore pressurized gas comprising; tubing mean received in the well; said tubing means having a gas inlet portion and a liquid discharge portion; said gas inlet portion connected to said well for receiving well bore pressurized gas; said tubing means having a small opening therein for receiving liquid from the well; a first valve connected to said liquid discharge portion; means for opening and closing said first valve whereby when said first valve is closed liquid will accumulate in said tubing means and when said first valve is opened gas from said gas inlet portion will force the liquid through said liquid discharge portion and out of the well.   
     
     
       9. An apparatus as set forth in claim 8 further including a second valve connected to said liquid discharge portion of said tubing means and to said well for applying well bore pressurized gas to said liquid discharge portion when said second valve is opened; said second valve being closed when said first valve is open. 
     
     
       10. An apparatus as set forth in claim 8 wherein said opening in said tubing is located in the vicinity of the lowest portion of said tubing in the well. 
     
     
       11. An apparatus as set forth in claim 8 wherein said well is a gas producing well, and further includes a pipe connected to said well for gathering gas. 
     
     
       12. An apparatus as set forth in claim 8 wherein said tubing means includes a U-shaped tube having at least two lines; one of the lines being said gas inlet portion and the other of the lines being said liquid discharge portion. 
     
     
       13. An apparatus as set forth in claim 12 further including a connector line attaching said gas inlet portion to said gas liquid discharge portion; said opening being located in said connector line. 
     
     
       14. An apparatus as set forth in claim 8 wherein said tubing means includes an outer tube and an inner tube; said inner tube being received in said outer tube. 
     
     
       15. An apparatus as set forth in claim 7 wherein said inner tube is said liquid discharge portion and the outer tube is said gas inlet portion. 
     
     
       16. An apparatus as set forth in claim 8 further including a first sensing means for sensing a predetermined amount of liquid in said tubing means; means for initiating the opening of said first valve in response to said first sensing means. 
     
     
       17. An apparatus as set forth in claim 16 further including a second valve connected to said liquid discharge line and to bore hole, said means for initiating also closing said second valve. 
     
     
       18. An apparatus as set forth in claim 16 wherein said means for initiating is a controller. 
     
     
       19. An apparatus as set forth in claim 18 wherein said controller initiates closing of said first valve after a predetermined time. 
     
     
       20. An apparatus as set forth in claim 18 further including a second sensing means located near said first valve; said second sensing means electrically connected to said controller for closing said first valve upon sensing the liquid passing through said liquid discharge portion. 
     
     
       21. An apparatus as set forth in claim 20 wherein said second valve is opened at the time that said first valve is closed in response to said second sensing means. 
     
     
       22. An apparatus as set forth in claim 18 further including a battery connected to said controller for auto controller. 
     
     
       23. An apparatus as set forth in claim 1 further including a liquid sensing means located near said first valve; said first valve being closed after a predetermined time after a response from said sensing means. 
     
     
       24. An apparatus as set forth in claim 23 further including a second valve connected to said liquid discharge line and to said bore hole; a controller; said sensing means electrically connected to said controller for closing said first valve after sensing liquid passing through the liquid discharge portion; said controller subsequently causing said second valve to open; said controller being programmed to initiate the pumping cycle by closing said second valve and subsequently opening said first valve. 
     
     
       25. An apparatus as set forth in claim 23 further including a well bore gas pressure sensor connected to said controller.